Fix `org-startup-with-latex-preview' handling

* lisp/org.el (org-mode): When honoring
  `org-startup-with-latex-preview', make sure to preview the whole
  buffer.

Reported-by: Diego Nicola Barbato
<http://permalink.gmane.org/gmane.emacs.orgmode/112925>

lisp/org.el

@@ -5679,7 +5679,7 @@ The following commands are available:
      (when org-startup-align-all-tables
        (org-table-map-tables #'org-table-align t))
      (when org-startup-with-inline-images (org-display-inline-images))
-     (when org-startup-with-latex-preview (org-toggle-latex-fragment))
+     (when org-startup-with-latex-preview (org-toggle-latex-fragment '(16)))
      (unless org-inhibit-startup-visibility-stuff (org-set-startup-visibility))
      (when org-startup-truncated (setq truncate-lines t))
      (when org-startup-indented (require 'org-indent) (org-indent-mode 1))